package com.hgy.stack;

import java.util.Scanner;

public class ArrayStackDemo {
    public static void main(String[] args) {

        ArrayStack stack = new ArrayStack(4);
        String key = "";
        boolean loop = true;
        Scanner scanner = new Scanner(System.in);

        while (loop){
            System.out.println("show：表示显示栈");
            System.out.println("exit：退出程序");
            System.out.println("push：表示添加数据到栈");
            System.out.println("pop：表示从栈取出数据");
            key = scanner.next();
            switch (key){
                case "show":
                    stack.list();
                    break;
                case "exit":
                    scanner.close();
                    loop = false;
                    break;
                case "push":
                    stack.push(scanner.nextInt());
                    break;
                case "pop":
                    try {
                        System.out.println("栈取出的数据为"+stack.pop());
                    }catch (Exception e){
                        System.out.println(e.getMessage());
                    }
                    break;
                default:
                    System.out.println("输入的命令错误，请重新输入！");
            }
        }
        System.out.println("程序结束！");
    }
}

class ArrayStack{
    private int maxSize;
    private int[] stack;
    private int top = -1;

    public ArrayStack(int maxSize){
        this.maxSize = maxSize;
        stack = new int[this.maxSize];
    }

    public boolean isFull(){
        return top == maxSize-1;
    }

    public boolean isEmpty(){
        return top == -1;
    }

    public void push(int value){
        if (isFull()){
            System.out.println("栈满");
            return;
        }
        top++;
        stack[top] = value;
    }

    public int pop(){
        if (isEmpty()){
            throw new RuntimeException("栈空，没有数据~");
        }
        int value = stack[top];
        top--;
        return value;
    }

    public void list(){
        if (isEmpty()){
            System.out.println("栈空");
            return;
        }
        int temp = top;
        while(temp!=-1){
            System.out.printf("stack[%d]=%d\n",temp, stack[temp--]);
        }
    }
}
